Variable speed motors capable of operating at multiple selectable speeds are well known in the art. It is also well known that a motor controller for a variable speed motor can store multiple operating profiles. For example, a motor controller may store a “quiet” profile that, when activated, configures the motor controller to operate the motor in a quiet mode, e.g., at a low speed setting. Another profile might be called “maximum” and would relate to operating the motor at a high speed.
Various operational profiles for a food waste disposal unit are disclosed in U.S. Pat. Nos. 6,481,652, 6,854,673, and 7,048,213, the entire disclosures of each of which are incorporated by reference herein. For example, U.S. Pat. No. 6,854,673 discloses a motor controller for operating a food waste disposer in operational modes such as soft start mode, optimized grinding mode, idle mode, rinse mode, and anti-jamming mode.
A motor controller may receive an instruction to activate a particular profile from an external electronic device. For example, a dishwashing machine may comprise a dishwasher control unit, a motor, and a motor controller. The dishwasher control unit sends instructions to the motor controller via low-voltage communication lines. The instructions may comprise an instruction to activate a particular stored profile from among a plurality of stored profiles.
The inventors herein have identified several problems with providing dedicated communication lines between a main control unit (e.g., dishwasher control unit) and a motor controller. For example, the communication lines are susceptible to electromagnetic interference and damage. Providing dedicated communication lines may also require communication hardware such as rs232 drivers, optocouplers, or can bus drivers.
In an exemplary embodiment, the inventors herein disclose an innovative technique for communication with a motor controller that does not require dedicated communication lines.
In an exemplary embodiment, the inventors herein disclose an innovative technique for communication with a motor controller by controlling the electrical power provided to the motor.
FIG. 1 depicts an exemplary circuit diagram for a device comprising an electric motor 109. The device comprises a main power supply 101 that may be an alternating current (AC) power supply as is known in the art. Main power supply 101 may or may not comprise a rectifier for converting AC power to direct current (DC) power. The device further comprises a device controller 103 that comprises logic for controlling the high-level operation of the device. For example, in a dishwasher, device controller 103 may comprise logic (such as a microcontroller) for receiving user input (e.g., via buttons and switches) and conducting the operation of various dishwasher components such as a soap dispenser, display lights, one or more water pumps, one or more relays, etc. Relay 105 is operable to connect or disconnect power lines 181 and 183 based on input on control line 191. Motor controller 107 controls the power delivered to motor 109. Device controller 103 operates relay 105 via control line 191 to connect or disconnect power to motor controller 107 and motor 109. Relay 105 may or may not be located within the same housing as device controller 103. Device controller 103 communicates with motor controller 107 via control lines 189. Motor controller 107 may comprise a memory for storing a plurality of motor operation profiles. Device controller 103 may send a profile selection instruction to motor controller 107 via control line 189. In response to such a profile selection instruction, motor controller 107 activates the designated profile and operates the motor 109 according to the profile.
The inventors herein disclose an innovative technique for instructing a motor controller to select an operational profile without a need for dedicated communication lines. In an exemplary embodiment, the motor controller is configured to select an operational profile based on changes in motor power status, as disclosed in detail herein.